CA2007405C - Mark reading device - Google Patents
Mark reading deviceInfo
- Publication number
- CA2007405C CA2007405C CA002007405A CA2007405A CA2007405C CA 2007405 C CA2007405 C CA 2007405C CA 002007405 A CA002007405 A CA 002007405A CA 2007405 A CA2007405 A CA 2007405A CA 2007405 C CA2007405 C CA 2007405C
- Authority
- CA
- Canada
- Prior art keywords
- laser
- scan
- laser beam
- reading device
- output energy
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
- G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
- G06K7/10544—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum
- G06K7/10821—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum further details of bar or optical code scanning devices
- G06K7/10851—Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K2207/00—Other aspects
- G06K2207/1018—Source control
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Electromagnetism (AREA)
- Artificial Intelligence (AREA)
- Toxicology (AREA)
- General Health & Medical Sciences (AREA)
- Health & Medical Sciences (AREA)
- Computer Vision & Pattern Recognition (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Mechanical Optical Scanning Systems (AREA)
- Character Input (AREA)
- Image Input (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
A mark reading device that reads marks such as a bar code, or the like on a remote surface. A
laser beam is outputted, deflected through a scan angle and the reflected energy is read at a detector. This energy is processed and converted to a usable format for input into a computer, cash register, or any type of data collection device. The present invention improves depth of field and readability by varying the output energy of the laser after each successive scan, thus providing a range of energy levels at the detector.
laser beam is outputted, deflected through a scan angle and the reflected energy is read at a detector. This energy is processed and converted to a usable format for input into a computer, cash register, or any type of data collection device. The present invention improves depth of field and readability by varying the output energy of the laser after each successive scan, thus providing a range of energy levels at the detector.
Description
2~ 7405 -MARR READING DEVI OE
BACRGROUND OF THE lNv~NlION
Field of The Invention The present invention relates to a mark reading device in which the output beam of a laser oscillating device is applied to an object to scan the surface thereof. The laser beam reflected therefrom is received, at a light detection device, to read marks such as characters, bar codes, or the like.
Description of Related Art The recent widespread use of computers has spurred the development and use of input devices such as character readers, bar code readers and the like. Such input devices are typically held in the operators hand for convenience and flexibility. Because of this, exact positioning and orientation are not possible. Thus, the reading device must be able to read over a wide range of distances and orientation angles to be reliable and practical. Previous mark reading devices have proved unreliable at reading surfaces at varying distances and angles. The laser output energy of such devices is fixed while in the scan mode.
Consequently, the energy of laser light received at the detector is a function of the distance between the reading device and the surface to be read and the incident angle of the surface relative to the laser beam. When such a device is too close to the surface that is to be read the detection device is saturated and the device fails to function. When the same device is too far away from, or at a high angle to, the surface that is to be read the reflected signal at the detection device is too low and again the device fails.
~)~
-The typical mark reading device found in the prior art consists of a laser oscillating device, a rotatable mirror for deflecting the laser beam output of the oscillating device through a predetermined scan angle, a light detection device for receiving the reflected laser beam and signal processing circuitry. The above elements can be incorporated into a stationary housing, a portable housing such as a "gun" configuration, or the like.
10SU~ARY OF THE INVENTION
The object of the present invention is to provide a mark reading device that will read bar codes, characters, or the like quickly and reliably at varying distances and angles of incidence. This objective is achieved by varying the output energy of the laser oscillating device after each scan so that an acceptable signal is received at the light detection device. A scan detection device is incorporated to send a signal to a controller indicating the end of each scan of the laser beam.
In turn, the controller will change the output energy of the laser oscillating device, in a predetermined manner, after each deflection of the beam. The variance of laser energy over several deflections, or scans, insures that a readable signal has been received at the light detection device during at least one scan.
The nature, principle, and utility of the present invention will become apparent from the following detailed description of its operation and the accompanying drawings.
~0(~)7405 BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE 1 is a perspective view of one embodiment of the present invention in a "gun"
style;
FIGURE 2 is a diagram illustrating a typical arrangement of a controller for controlling the output of a laser oscillating device in response to a signal from a scan detecting light receiving element;
Figure 3(A) is a graph illustrating a typical output signal of the scan detecting element, verses time, during scan mode in the present invention;
Figure 3(B) is a graph illustrating a typical output signal from the controller, verses time, during scan mode in the present invention;
FIGURE 3(C) is a graph illustrating typical output energy levels of the laser oscillating device, verses time, during scan mode in the present invention;
FIGURE 4(A) is a diagram illustrating an example of a logic circuit; and FIGURE 4(B) is a diagram illustrating another example of a logic circuit.
DETATT~n DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGURE 1 illustrates a preferred embodiment of the present invention in a hand held ~gun" type of device. When the trigger 8 is depressed a motor 11 is driven to rotate a polygon mirror 4.
Simultaneously, the laser oscillating device 2 outputs a laser beam. The laser beam thus outputted is reflected by the surfaces of the mirror 4 , which is rotating, and the laser beam is thusly deflected ~ through a scan angle in the scanning mode. The mirror 4 could also be of a single surface and the motor 11 of an oscillating type. The present invention encompasses any method of moving a laser S beam through a scan angle, of which many are known in the prior art. The laser beam deflected off of the mirror 4 passes through opening 13 to the surface 6 that is to be read and is reflected thereby and received by a light detection device 7 in the mark reading device. The light detection device 7 outputs a signal proportional to the energy of the reflected laser light. This signal is conditioned and processed, in the processing circuit 9, into a standard, usable signal for input into a computer, cash register, or the like through cable 10 .
FIGURE 2 illustrates a block diagram of a circuit used to vary the output of the laser oscillating device 2 in response to a scan termination signal. The scan detection device element 12 is a light detecting device, such as a photocell. The output of the laser oscillating device 2 is moved through the predetermined scan angle as a result of deflection off of the rotating mirror 4. Whenever receiving the laser beam the scan detection device 12 outputs a pulse-like scan detection signal as shown in FIGURE 3(A). This signal may be amplified and conditioned as necessary by a signal conditioning circuit 21. The output of the signal conditioning circuit 21 is then directed to a logic circuit 22 that converts the pulses, corresponding to scan terminations, into a predetermined (or preprogrammed) set of control instructions for input into the control circuit 23.
The combination of the logic circuit 22 and the ~007405 control circuit 23 may be defined as the controller 20.
The output of the controller 20 is a step-like curve of varying control data to the laser oscillating 2 device where each successive step corresponds to a scan termination as seen in FIGURE
BACRGROUND OF THE lNv~NlION
Field of The Invention The present invention relates to a mark reading device in which the output beam of a laser oscillating device is applied to an object to scan the surface thereof. The laser beam reflected therefrom is received, at a light detection device, to read marks such as characters, bar codes, or the like.
Description of Related Art The recent widespread use of computers has spurred the development and use of input devices such as character readers, bar code readers and the like. Such input devices are typically held in the operators hand for convenience and flexibility. Because of this, exact positioning and orientation are not possible. Thus, the reading device must be able to read over a wide range of distances and orientation angles to be reliable and practical. Previous mark reading devices have proved unreliable at reading surfaces at varying distances and angles. The laser output energy of such devices is fixed while in the scan mode.
Consequently, the energy of laser light received at the detector is a function of the distance between the reading device and the surface to be read and the incident angle of the surface relative to the laser beam. When such a device is too close to the surface that is to be read the detection device is saturated and the device fails to function. When the same device is too far away from, or at a high angle to, the surface that is to be read the reflected signal at the detection device is too low and again the device fails.
~)~
-The typical mark reading device found in the prior art consists of a laser oscillating device, a rotatable mirror for deflecting the laser beam output of the oscillating device through a predetermined scan angle, a light detection device for receiving the reflected laser beam and signal processing circuitry. The above elements can be incorporated into a stationary housing, a portable housing such as a "gun" configuration, or the like.
10SU~ARY OF THE INVENTION
The object of the present invention is to provide a mark reading device that will read bar codes, characters, or the like quickly and reliably at varying distances and angles of incidence. This objective is achieved by varying the output energy of the laser oscillating device after each scan so that an acceptable signal is received at the light detection device. A scan detection device is incorporated to send a signal to a controller indicating the end of each scan of the laser beam.
In turn, the controller will change the output energy of the laser oscillating device, in a predetermined manner, after each deflection of the beam. The variance of laser energy over several deflections, or scans, insures that a readable signal has been received at the light detection device during at least one scan.
The nature, principle, and utility of the present invention will become apparent from the following detailed description of its operation and the accompanying drawings.
~0(~)7405 BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE 1 is a perspective view of one embodiment of the present invention in a "gun"
style;
FIGURE 2 is a diagram illustrating a typical arrangement of a controller for controlling the output of a laser oscillating device in response to a signal from a scan detecting light receiving element;
Figure 3(A) is a graph illustrating a typical output signal of the scan detecting element, verses time, during scan mode in the present invention;
Figure 3(B) is a graph illustrating a typical output signal from the controller, verses time, during scan mode in the present invention;
FIGURE 3(C) is a graph illustrating typical output energy levels of the laser oscillating device, verses time, during scan mode in the present invention;
FIGURE 4(A) is a diagram illustrating an example of a logic circuit; and FIGURE 4(B) is a diagram illustrating another example of a logic circuit.
DETATT~n DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGURE 1 illustrates a preferred embodiment of the present invention in a hand held ~gun" type of device. When the trigger 8 is depressed a motor 11 is driven to rotate a polygon mirror 4.
Simultaneously, the laser oscillating device 2 outputs a laser beam. The laser beam thus outputted is reflected by the surfaces of the mirror 4 , which is rotating, and the laser beam is thusly deflected ~ through a scan angle in the scanning mode. The mirror 4 could also be of a single surface and the motor 11 of an oscillating type. The present invention encompasses any method of moving a laser S beam through a scan angle, of which many are known in the prior art. The laser beam deflected off of the mirror 4 passes through opening 13 to the surface 6 that is to be read and is reflected thereby and received by a light detection device 7 in the mark reading device. The light detection device 7 outputs a signal proportional to the energy of the reflected laser light. This signal is conditioned and processed, in the processing circuit 9, into a standard, usable signal for input into a computer, cash register, or the like through cable 10 .
FIGURE 2 illustrates a block diagram of a circuit used to vary the output of the laser oscillating device 2 in response to a scan termination signal. The scan detection device element 12 is a light detecting device, such as a photocell. The output of the laser oscillating device 2 is moved through the predetermined scan angle as a result of deflection off of the rotating mirror 4. Whenever receiving the laser beam the scan detection device 12 outputs a pulse-like scan detection signal as shown in FIGURE 3(A). This signal may be amplified and conditioned as necessary by a signal conditioning circuit 21. The output of the signal conditioning circuit 21 is then directed to a logic circuit 22 that converts the pulses, corresponding to scan terminations, into a predetermined (or preprogrammed) set of control instructions for input into the control circuit 23.
The combination of the logic circuit 22 and the ~007405 control circuit 23 may be defined as the controller 20.
The output of the controller 20 is a step-like curve of varying control data to the laser oscillating 2 device where each successive step corresponds to a scan termination as seen in FIGURE
3(B). Note however, that the control data to the laser oscillating device 2 is constant over the period of each scan. This data may be any type of physical or electrical control data such as voltage, current, binary data, or the like. The output power of the laser oscillating device 2 is proportional to the control data received from the controller 20. As a result, the output power of the laser is also a step-like function where each successive step corresponds to a scan termin~tion as seen in FIGURE
3(C). Because the output power of the laser oscillating device 2 is varied in this manner the reflected beam received by the light detection device element 7 is likely to be of an acceptable energy level for a proper read without the necessity of moving the reading device.
The magnitude of the control data and the number of step-like transitions may be selected to r~imi ze readability and minimize time between reads depending on the range of distances to be read. One possible example is illustrated in FIGURE 3(B) and FIGURE 3(C) where control data ~1 corresponds to a laser output power of Pl that is lower than the usually set laser output, control data ~2 corresponds to a laser output power P2 that is equal to the usual laser output value, and control data ~3 corresponds to a laser output value P3 that is higher than the usual laser output value. Most laser oscillating devices in use today are capable of an output energy higher than the usual output energy 2~Q74a~
-- value. Selecting such an output energy continuously can reduce the life of the laser. In the present invention the higher laser output energy will be intermittent and will come only after a period of lower laser output values. This method of operation should not significantly reduce the life of most laser oscillating devices. The actual values of the control data and the laser output are readily determined by one skilled in the art with a minimum of experimentation or calculation.
FIGURE 4(A) illustrates one method that may be employed in the logic circuit 22. A switching operation is carried out in response to the scan detection signal from the signal conditioning circuit 21. Each scan detection signal operates the switching operation so as to different drive voltages to the control circuit 23. Of course the number of different voltages and their magnitudes will be selected for the specific application.
Figure 4(B) illustrates another possible method that may be employed in the logic circuit. In this case the logic circuit is made up of a counter 22a and a digital to analog converter 22b. The counter 22a counts a specified plurality of scan detection signals and its output count is directed to the digital to analog converter 22b which outputs a corresponding signal to the control circuit 23.
After the specified plurality of scan detection signals is detected, (e.g. 3) the counter is automatically reset and counting begins again.
While a preferred embodiment of the present invention is described above it will be obvious to those skilled in the art that various modifications may be made therein without departing from the scope and spirit of the present invention.
3(C). Because the output power of the laser oscillating device 2 is varied in this manner the reflected beam received by the light detection device element 7 is likely to be of an acceptable energy level for a proper read without the necessity of moving the reading device.
The magnitude of the control data and the number of step-like transitions may be selected to r~imi ze readability and minimize time between reads depending on the range of distances to be read. One possible example is illustrated in FIGURE 3(B) and FIGURE 3(C) where control data ~1 corresponds to a laser output power of Pl that is lower than the usually set laser output, control data ~2 corresponds to a laser output power P2 that is equal to the usual laser output value, and control data ~3 corresponds to a laser output value P3 that is higher than the usual laser output value. Most laser oscillating devices in use today are capable of an output energy higher than the usual output energy 2~Q74a~
-- value. Selecting such an output energy continuously can reduce the life of the laser. In the present invention the higher laser output energy will be intermittent and will come only after a period of lower laser output values. This method of operation should not significantly reduce the life of most laser oscillating devices. The actual values of the control data and the laser output are readily determined by one skilled in the art with a minimum of experimentation or calculation.
FIGURE 4(A) illustrates one method that may be employed in the logic circuit 22. A switching operation is carried out in response to the scan detection signal from the signal conditioning circuit 21. Each scan detection signal operates the switching operation so as to different drive voltages to the control circuit 23. Of course the number of different voltages and their magnitudes will be selected for the specific application.
Figure 4(B) illustrates another possible method that may be employed in the logic circuit. In this case the logic circuit is made up of a counter 22a and a digital to analog converter 22b. The counter 22a counts a specified plurality of scan detection signals and its output count is directed to the digital to analog converter 22b which outputs a corresponding signal to the control circuit 23.
After the specified plurality of scan detection signals is detected, (e.g. 3) the counter is automatically reset and counting begins again.
While a preferred embodiment of the present invention is described above it will be obvious to those skilled in the art that various modifications may be made therein without departing from the scope and spirit of the present invention.
Claims (3)
1. A mark reading device comprising;
a laser oscillating unit outputting a laser beam;
deflecting means for deflecting said laser beam, cyclicly, through a predetermined scan angle;
receiving means for reading said laser beam upon reflection from an object surface;
scan detecting means for outputting a scan termination signal after each of said scans; and controller means for varying the output energy of said laser beam in response to said scan termination signal;
a laser oscillating unit outputting a laser beam;
deflecting means for deflecting said laser beam, cyclicly, through a predetermined scan angle;
receiving means for reading said laser beam upon reflection from an object surface;
scan detecting means for outputting a scan termination signal after each of said scans; and controller means for varying the output energy of said laser beam in response to said scan termination signal;
2. A mark reading device as described in claim 1;
wherein said controller means is configured so as to vary the output energy of said laser beam by an incremental step in response to each of said scan termination signals.
wherein said controller means is configured so as to vary the output energy of said laser beam by an incremental step in response to each of said scan termination signals.
3. A mark reading device as described in claim 1;
wherein said controller means is configured so as to vary the output energy of said laser beam by an incremental step in response to each of said scan termination signals whereby;
at least one the incremental steps corresponds to an energy level lower than the usually set laser output energy level;
at least one of the incremental steps corresponds to an energy level equal to the usually set laser output energy level; and at least one of the incremental steps corresponds to an energy level higher than the usually set laser output energy level.
wherein said controller means is configured so as to vary the output energy of said laser beam by an incremental step in response to each of said scan termination signals whereby;
at least one the incremental steps corresponds to an energy level lower than the usually set laser output energy level;
at least one of the incremental steps corresponds to an energy level equal to the usually set laser output energy level; and at least one of the incremental steps corresponds to an energy level higher than the usually set laser output energy level.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP004015/89 | 1989-01-10 | ||
| JP1004015A JPH07104900B2 (en) | 1989-01-10 | 1989-01-10 | Symbol reader |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2007405A1 CA2007405A1 (en) | 1990-07-10 |
| CA2007405C true CA2007405C (en) | 1996-01-16 |
Family
ID=11573146
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002007405A Expired - Fee Related CA2007405C (en) | 1989-01-10 | 1990-01-09 | Mark reading device |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US5148008A (en) |
| EP (1) | EP0378199B1 (en) |
| JP (1) | JPH07104900B2 (en) |
| CA (1) | CA2007405C (en) |
| DE (1) | DE69021090T2 (en) |
| HK (1) | HK80996A (en) |
Families Citing this family (29)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6247647B1 (en) * | 1988-09-19 | 2001-06-19 | Symbol Technologies, Inc. | Scan pattern generator convertible between multiple and single line patterns |
| CA2056842A1 (en) * | 1991-02-07 | 1992-08-08 | Jay M. Eastman | System for scanning and reading symbols, such as bar codes, which is adapted to be configured in a hand held unit and can automatically read symbols on objects which are placed inthe detection zone of the unit |
| US5200597A (en) * | 1991-02-07 | 1993-04-06 | Psc, Inc. | Digitally controlled system for scanning and reading bar codes |
| WO1993017396A1 (en) * | 1992-02-21 | 1993-09-02 | Spectra-Physics Scanning Systems, Inc. | Bar code scanner |
| JP3235249B2 (en) * | 1992-12-18 | 2001-12-04 | 株式会社デンソー | Optical information reader |
| GB2274937B (en) * | 1993-01-23 | 1996-11-13 | Nippon Sheet Glass Co Ltd | Liquid crystal display |
| US5546217A (en) * | 1993-11-05 | 1996-08-13 | Decagon Devices, Inc. | Laser scanning apparatus |
| JP3183767B2 (en) * | 1994-02-21 | 2001-07-09 | 富士通株式会社 | Laser beam scanning device |
| US6199759B1 (en) * | 1994-08-17 | 2001-03-13 | Metrologic Instruments, Inc. | Bar code symbol scanning system having a holographic laser scanning disc utilizing maximum light collection surface area thereof and having scanning facets with optimized light collection efficiency |
| US6073846A (en) * | 1994-08-17 | 2000-06-13 | Metrologic Instruments, Inc. | Holographic laser scanning system and process and apparatus and method |
| US6158659A (en) * | 1994-08-17 | 2000-12-12 | Metrologic Instruments, Inc. | Holographic laser scanning system having multiple laser scanning stations for producing a 3-D scanning volume substantially free of spatially and temporally coincident scanning planes |
| US6003772A (en) * | 1994-08-17 | 1999-12-21 | Metrologic Instruments, Inc. | Holographic laser scanning system employing holographic scanning disc having dual-fringe contrast regions for optimized laser beam scanning and light collection operations |
| US6547144B1 (en) | 1994-08-17 | 2003-04-15 | Metrologic Instruments, Inc. | Holographic laser scanning system for carrying out light collection operations with improved light collection efficiency |
| US6006993A (en) * | 1994-08-17 | 1999-12-28 | Metrologic Instruments, Inc. | Holographic laser scanning system for carrying out laser beam scanning operations with improved scan angle multiplication efficiency and carrying out light collection operations with improved light collection efficiency |
| US6085978A (en) * | 1994-08-17 | 2000-07-11 | Metrologic Instruments, Inc. | Holographic laser scanners of modular construction and method and apparatus for designing and manufacturing the same |
| US5612529A (en) * | 1994-10-31 | 1997-03-18 | Psc Inc. | System for bar code reading and scanning with automatic gain control |
| US5581071A (en) * | 1994-12-06 | 1996-12-03 | International Business Machines Corporation | Barcode scanner with adjustable light source intensity |
| US5834750A (en) * | 1995-02-28 | 1998-11-10 | Psc, Inc. | Bar code scanning system for automatically maintaining constant the amplitude of light reflected from a bar code |
| US6848014B2 (en) | 2001-01-23 | 2005-01-25 | Symbol Technologies, Inc. | Adapter unit for a personal digital assistant having automatically configurable application buttons |
| US7185820B1 (en) * | 1997-06-26 | 2007-03-06 | Symbol Technologies, Inc. | Data acquisition apparatus |
| US6857572B2 (en) * | 1998-12-03 | 2005-02-22 | Metrologic Instruments, Inc. | Automatically-activated hand-supportable laser scanning bar code symbol reading system with omnidirectional and unidirectional scanning modes in addition to a data transmission activation switch |
| US7097105B2 (en) * | 1998-12-03 | 2006-08-29 | Metrologic Instruments, Inc. | Automatically-activated hand-supportable omni-directional laser scanning bar code symbol reader having a user-selectable linear scanning menu-reading mode supported by a stroboscopically-pulsed omni-directional laser scanning pattern for improved bar code symbol navigation and alignment during menu-reading operations |
| US6905071B2 (en) * | 1998-12-03 | 2005-06-14 | Metrologic Instruments, Inc. | Automatically-activated hand-supportable multi-mode laser scanning bar code symbol reading system |
| US20050275625A1 (en) * | 2004-06-15 | 2005-12-15 | Koenig Douglas W | Ergonomic computer input device having pistol-type grip |
| US20070047605A1 (en) * | 2005-08-26 | 2007-03-01 | Edward Barkan | Laser power control arrangements in electro-optical readers |
| US7806585B2 (en) * | 2007-06-22 | 2010-10-05 | Decagon Devices, Inc. | Apparatus, method, and system for measuring water activity and weight |
| US8579198B2 (en) * | 2010-12-01 | 2013-11-12 | Symbol Technologies, Inc. | Enhanced laser barcode scanning |
| US8752766B2 (en) | 2012-05-07 | 2014-06-17 | Metrologic Instruments, Inc. | Indicia reading system employing digital gain control |
| US8789759B2 (en) | 2012-05-18 | 2014-07-29 | Metrologic Instruments, Inc. | Laser scanning code symbol reading system employing multi-channel scan data signal processing with synchronized digital gain control (SDGC) for full range scanning |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54124930A (en) * | 1978-03-22 | 1979-09-28 | Mitsubishi Heavy Ind Ltd | Photo sensor system |
| JPS54132131A (en) * | 1978-04-05 | 1979-10-13 | Sumitomo Electric Ind Ltd | Optical information reading device |
| DE2816325A1 (en) * | 1978-04-14 | 1979-10-18 | Computer Ges Konstanz | DEVICE FOR SCANNING PATTERNS WITH A REGULATED LIGHT SOURCE |
| US4481667A (en) * | 1981-12-21 | 1984-11-06 | Autronics Corporation | Item counting apparatus |
| US4677287A (en) * | 1982-07-14 | 1987-06-30 | Canon Kabushiki Kaisha | Document reader with light source control |
| JPS61123359A (en) * | 1984-11-20 | 1986-06-11 | Brother Ind Ltd | Optical reader |
| JPS61201382A (en) * | 1985-03-04 | 1986-09-06 | Ricoh Co Ltd | Optical reader |
| DE3602008A1 (en) * | 1986-01-23 | 1987-07-30 | Sick Optik Elektronik Erwin | OPTICAL SCANNER WITH A MIRROR WHEEL |
| JPS62259191A (en) * | 1986-05-02 | 1987-11-11 | Toshiba Corp | Scan pattern reader |
| US4820911A (en) * | 1986-07-11 | 1989-04-11 | Photographic Sciences Corporation | Apparatus for scanning and reading bar codes |
| JP2624669B2 (en) * | 1987-03-10 | 1997-06-25 | キヤノン株式会社 | Image reading device |
| JPS63225925A (en) * | 1987-03-16 | 1988-09-20 | Olympus Optical Co Ltd | Method for recording data on optical card |
| US4933538A (en) * | 1988-10-21 | 1990-06-12 | Symbol Technologies, Inc. | Scanning system with adjustable light output and/or scanning angle |
-
1989
- 1989-01-10 JP JP1004015A patent/JPH07104900B2/en not_active Expired - Lifetime
-
1990
- 1990-01-09 CA CA002007405A patent/CA2007405C/en not_active Expired - Fee Related
- 1990-01-10 EP EP90100451A patent/EP0378199B1/en not_active Expired - Lifetime
- 1990-01-10 DE DE69021090T patent/DE69021090T2/en not_active Expired - Fee Related
-
1991
- 1991-11-12 US US07/789,803 patent/US5148008A/en not_active Expired - Fee Related
-
1996
- 1996-05-09 HK HK80996A patent/HK80996A/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| HK80996A (en) | 1996-05-17 |
| EP0378199A3 (en) | 1993-09-01 |
| US5148008A (en) | 1992-09-15 |
| EP0378199B1 (en) | 1995-07-26 |
| EP0378199A2 (en) | 1990-07-18 |
| JPH02183386A (en) | 1990-07-17 |
| JPH07104900B2 (en) | 1995-11-13 |
| DE69021090D1 (en) | 1995-08-31 |
| CA2007405A1 (en) | 1990-07-10 |
| DE69021090T2 (en) | 1995-12-21 |
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| Date | Code | Title | Description |
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| EEER | Examination request | ||
| MKLA | Lapsed |